Implementation of DNA cytometric measurements in fine-needle aspiration biopsy diagnostics of breast disease

Abstract

For this study, the diagnostic protocol included fine-needle aspiration biopsy (FNAB) and DNA cytometric measurements. The objective of the study was to improve the diagnostic sensitivity of FNAB. Sixty-eight FNAB samples were stained using the Feulgen stain, and DNA histograms were produced by selecting the nuclei of cell groups and free cells separately. Among 28 samples that were classified as definitely benign (n = 17 samples) or atypical but benign (n = 11 samples), DNA cytometry generally showed diploid/peridiploid peaks. Three of those samples were associated later with carcinoma. In those samples DNA cytometry did not improve sensitivity. Among moderately atypical samples (n = 17 samples), 8 samples were diagnosed later as carcinoma. DNA cytometry helped the diagnostic procedure in 62.5% of those samples. Among 21 samples that were classified as highly suspicious (n = 10 samples) or definitely malignant (n = 11 samples), DNA cytometry generally showed atypical DNA histograms (20 of 21 histograms), and DNA cytometry supported the diagnosis of carcinoma in 95.2%. Histograms that were based on free cells frequently were more abnormal compared with histograms that were based on cell groups. Histologically verified benign lesions also could show abnormalities in DNA histograms. Accepting wider gates than are used normally for primarily Feulgen stained samples on these restained samples resulted in improved specificity, efficiency, and predictive values. DNA cytometry has a potential to support the differential diagnosis of breast lesions, and sampling of free cells increases sensitivity. Benign breast lesions (fibrocystic disease, fibroadenoma) included DNA-cytometrically abnormal cell clones and showed tendencies toward polyploidy, which should be included in the diagnostic criteria.